Introduction

The Cisco MWR 1900 Mobile Wireless Edge Router running Cisco IOS Release 12.2(8) MC2 or a later Cisco IOS Release 12.2 MC is a networking platform optimized for use in mobile wireless networks. It extends IP connectivity to the cell site and Base Transceiver Station (BTS), and through a Fast Ethernet interface to the BTS, provides bandwidth-efficient IP transport of voice and data bearer traffic, as well as maintenance, control, and signalling traffic, over the leased line backhaul network between the BTS and leased line termination and aggregation node via compression (cRTP/cUDP) and packet multiplexing (PPPMux and MLPPP). It supports a limited set of interfaces and protocols, but offers high performance at a low cost while meeting the critical requirements for deployment in cell sites, including small size, extended operating temperature range, high availability, and DC input power flexibility.

System Configuration Requirements

The Cisco MWR 1900 Mobile Wireless edge router requires the following system configuration:

New Features in the Cisco MWR 1900 Router with Cisco Release 12.2 MC Software

The software running on the Cisco MWR 1900 router consists of two components: Cisco IOS software running on the MIPs-based route processor portion of the router hardware, and microcode running on the Cisco network processor, also known as Parallel eXpress Forwarding (PXF). Because the Cisco MWR 1900 router is designed specifically for use in an IP-RAN in the BTS, it is customized for performance, high-availability, quality of service, and link efficiency.

For detailed descriptions of each of these features, see the Cisco MWR 1900 Mobile Wireless Edge Router Software Configuration Guide.

Standard Cisco IOS software features supported in this release include:

–IP Fragmentation

–IP Multicast

–IGMP

–MLP, PPP Control Path (IPCP, NCP, LCP, CLNS)

–HSRP

–OSPF

–DHCP

–CDP

–NTP

–SNMP

•Network Processor Software

The following features are supported in the network processor:

–MAC Classify

–ICMP

–FIB (CEF)

–Load-balancing

–MAC Rewrite

–QoS Matching

–QoS Actions

–Statistic maintenance

–Ipv4

–MLPPP

–MLP, PPP Data Path (MLP LFI is not supported)

–PPPmux

–cRTP/cUDP

•Redundancy support

•Cisco Hot Standby Router Protocol (HSRP) support

•MIB support

Limitations, Restrictions, and Important Notes

Caution The Cisco MWR 1900 router does not support online insertion and removal (OIR) of WAN interface cards. Any attempt to perform OIR on a card in a powered up router might cause damage to the card.

Caution Removing the compact flash from the Cisco MWR 1900 router during a read/write operation might corrupt the contents of the compact flash, rendering it useless. To recover from an accidental removal of or corruption to the compact flash, a maintenance spare with the appropriate bootable Cisco IOS software image might be needed.

Unsupported Cisco IOS Software Features

The Cisco MWR 1900 router requires a special version of Cisco IOS software. Not all Cisco IOS software features can be used with the Cisco MWR 1900 router as the core routing is handled by the network processor. The following standard Cisco IOS software features are not supported on the Cisco MWR 1900 router:

•Security Access Control Lists

•MPLS

•802.1Q VLANs

•Frame Relay (FR)

•MLP LFI

•ATM

Upgrading the VWIC-2MFT-T1-DIR Microcode

When upgrading the image on your Cisco MWR 1900 router, power cycle the router or perform a microcode reload on the VWIC-2MFT-T1-DIR to ensure that the firmware for the VWIC-2MFT-T1-DIR is updated during the upgrade.

Disabling PPP Multiplexing

To fully disable PPP multiplexing (PPPMux), issue the no ppp mux command on the T1 interfaces of the routers at both ends of the T1 link. If PPP multiplexing remains configured on one side of the link, that side will offer to receive PPP multiplexed packets.

MLP LFI Support

MLP LFI is not supported by the Cisco MWR 1900 router. Therefore, MLP LFI must be disabled on peer devices connecting to the Cisco MWR 1900 router T1 MLP connections.

Caveats in Cisco IOS Release 12.2(8)MC2a

The following sections list and describe the open and closed caveats for the Cisco MWR 1900 router running Cisco IOS Release 12.2(8)MC2a. Only severity 1 through 3 caveats are included.

Caveats describe unexpected behavior in Cisco IOS software releases. Severity 1 caveats are the most serious caveats, severity 2 caveats are less serious, and severity 3 caveats are the least serious of these three severity levels.

Caveats in Cisco IOS Releases 12.2 and 12.2 T are also in Cisco IOS Release 12.2(8)MC2a. For information on caveats in Cisco IOS Release 12.2, see Caveats for Cisco IOS Release 12.2. For information on caveats in Cisco IOS Release 12.2 T, see Caveats for Cisco IOS Release 12.2 T. These two documents list severity 1 and 2 caveats and are located on CCO and the Documentation CD-ROM.

Note If you have an account with Cisco.com, you can use Bug Navigator II to find caveats of any severity for any release. To reach Bug Navigator II, Login to Cisco.com and click Software Center: Cisco IOS Software: Cisco Bugtool Navigator II. Another option is to go directly to http://www.cisco.com/support/bugtools.

Open Caveats

The caveats listed in this section are open in Release 12.2(8)MC2a.

•CSCdw34503

When using an extended ACL with the access-group command to define traffic using the class policy-map configuration command, the Cisco MWR 1900 router crashes to ROMmon. This condition happens because extended ACLs are currently not supported.

Workaround: The access-group command is not part of the IP-RAN configuration. However, if using the command, use only with standard ACLs.

•CSCdw56881

When traffic shaping is applied to an MLP output interface, the shaped output rate might be slightly higher than that defined. This condition occurs because the data rate to that interface is greater than the shaping rate.

Workaround: There is currently no workaround.

•CSCdx71203

An MLP bundle might occasionally have a few inactive links. This condition causes the bandwidth of the multilink bundle to be incorrect for the number of T1 interfaces configured. This condition occurs when one or more T1 links of an MLP bundle have their encapsulation changed to PPP (Encapsulation Type 5) instead of MLP (Encapsulation type 12).

Workaround: Issue a shut/no shut of the multilink bundle to cause the inactive links to become active links of the bundle.

•CSCdx85735

When the class-default queue is used with other class-based queues, the class-default queue's committed information rate (CIR) and the excess information rate are not configured correctly.

Workaround: Manually configure the committed information rate using the shape class-map configuration command. The excess information rate cannot be manually configured, therefore, there is no workaround for it not configuring correctly.

•CSCdy09568

QoS class-based WFQs configured with a low percentage of bandwidth are unable to use the unused bandwidth from queues assigned a high percentage of the bandwidth.

Workaround: Deconfigure QoS on the output interface.

Resolved Caveats

The caveats listed in this section are resolved in Release 12.2(8)MC2a.

•CSCdw90497

When keepalive is enabled on a serial interface, the interface might alternate between an up and down state during heavy traffic conditions.

•CSCdx27723

The PXF locks up, I/O memory lowers, and a CPU exception occurs when removing a serial link from an MLP bundle while bi-directional traffic is being processed.

•CSCdx62732

When using MLP as the transport protocol, the PPP multiplexing ratio is less than expected when small packets are received. This condition occurs under normal operation (with cUDP and 18-bytes payload). The occurrence of multiple traffic flows that are in separate QoS classes might add to this condition.

•CSCdx74802

When cUDP and PPP multiplexing/demultiplexing are enabled and startup occurs during a period of heavy UDP traffic, valid cUDP traffic flow might be corrupted in the PXF.

•CSCdx80216

When PPP multiplexing/demultiplexing and cUDP are configure on an MLP bundle and a very small number of UDP traffic flows are sent from the MWR 1900 router to the MGX, occasionally a couple of packets on a flow might be dropped at the MGX because they were sent in the incorrect order by the MWR 1900 router.

•CSCdx88825

When QoS (Low latency queueing [LLQ]/class-based WFQ [CBWFQ]) is configured on an output interface, drops might occur before they should on the priority queue during periods of high data rates.

•CSCdy20529

Fatal hardware exception errors (such as a parity errors) on the PXF do not cause an automatic reload of the PXF microcode or the generation of a pxf_crashinfo file.

•CSCdy23865

When cUDP is enabled, multicast packets are received by the Cisco MWR 1900 router on the multilink bundle, but are not forwarded out the FE ports.

•CSCdy24575

The values specified using the bandwidth policy-map class configuration command are not used for single T1 multilink bundles and the values display as 0 when the show policy-map interface command is entered for the interface.

Troubleshooting

Collecting Data for Router Issues

To collect data for reporting router issues, issue the following command:

•show tech-support—Displays general information about the router when it reports a problem.

Collecting Data for Redundancy Issues

To collect data for redundancy-related issues, issue the following commands while in EXEC mode:

To collect data for ROMmon issues, issue the following command while in EXEC mode:

•showmon— Displays currently selected ROM monitor.

Collecting Data for Router Rebooting to ROMmon

If a router reboot to ROMmon occurs, issue the dir device ID command where device ID is slot0:, and look for the router processor or network processor exception file (crashinfo* or pxf_crashinfo* respectively). Once you have located one of these files, you can email the file along with a description of the problem to your Cisco representative.

Documentation Updates

There are no documentation updates at this time.

Related Documentation

The following sections describe the documentation available for the Cisco MWR 1900 Mobile Wireless Edge Router. These documents consist of hardware and software installation guides, Cisco IOS configuration guides and command references, system error messages, and other documents.

Documentation is available as printed manuals or electronic documents.

Platform-Specific Documents

These documents are available for the Cisco MWR 1900 Mobile Wireless Edge Router on Cisco.com and the Documentation CD-ROM:

Feature Modules

Feature modules describe new features supported by Cisco IOS Release 12.2 MC and are updates to the Cisco IOS documentation set. A feature module consists of an overview of the feature, configuration tasks, and a command reference.

On Cisco.com at:

Technical Documents: Cisco IOS Software: Cisco IOS Release 12.2: New Feature Documentation: New Features in 12.2-Based Limited Lifetime Releases: New Features in Release 12.2 MC: New Features in Release 12.2 MC2

On the Documentation CD-ROM at:

Cisco Product Documentation: Cisco IOS Software Configuration: Cisco IOS Release 12.2: New Feature Documentation: New Features in 12.2-Based Limited Lifetime Releases: New Features in Release 12.2 MC: New Features in Release 12.2 MC2

Obtaining Documentation

These sections explain how to obtain documentation from Cisco Systems.

World Wide Web

You can access the most current Cisco documentation on the World Wide Web at this URL:

Documentation CD-ROM

Cisco documentation and additional literature are available in a Cisco Documentation CD-ROM package, which is shipped with your product. The Documentation CD-ROM is updated monthly and may be more current than printed documentation. The CD-ROM package is available as a single unitor through an annual subscription.

Obtaining Technical Assistance

Cisco provides Cisco.com as a starting point for all technical assistance. Customers and partners can obtain online documentation, troubleshooting tips, and sample configurations from online tools by usingthe Cisco Technical Assistance Center (TAC) Web Site. Cisco.com registered users have complete access to the technical support resources on the Cisco TAC Web Site.

Cisco.com

Cisco.com is the foundation of a suite of interactive, networked services that provides immediate, open access to Cisco information,networking solutions, services, programs, and resources at any time, from anywhere in the world.

Cisco.com is a highly integrated Internet application and a powerful, easy-to-use tool that provides a broad range of features and services to help you with these tasks:

Technical Assistance Center

The Cisco Technical Assistance Center (TAC) is available to all customers who need technical assistance with a Cisco product, technology, or solution. Two levels of support are available: the Cisco TAC Web Site and the Cisco TAC Escalation Center.

Cisco TAC inquiries are categorized according to the urgency of the issue:

•Priority level 2 (P2)—Your production network is severely degraded, affecting significant aspects of business operations. No workaround is available.

•Priority level 1 (P1)—Your production network is down, and a critical impact to business operations will occur if service is not restored quickly. No workaround is available.

The Cisco TAC resource that you choose is based on the priority of the problem and the conditions of service contracts, when applicable.

Cisco TAC Web Site

You can use the Cisco TAC Web Site to resolve P3 and P4 issues yourself, saving both cost and time. The site provides around-the-clock access to online tools, knowledge bases, and software. To access the Cisco TAC Web Site, go to this URL:

All customers, partners, and resellers who have a valid Cisco service contract have complete access to the technical support resources on the Cisco TAC Web Site. The Cisco TAC Web Site requires a Cisco.com login ID and password. If you have a valid service contract but do not have a login ID or password, go to this URL to register:

Before calling, please check with your network operationscenter to determine the level of Cisco support services to which your company is entitled: for example, SMARTnet, SMARTnet Onsite, or Network Supported Accounts (NSA). When you call the center, please have available your service agreement number and your product serial number.

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